The present invention pertains to a process for manufacturing a warning device for a divided highway, especially a process for manufacturing a warning device in different colors in order to match the traffic signs.
At present two kinds of warning devices are available for paving on divided highways: one is a white warning device exclusively used on a freeway, another one is the grass green warning device of South African origin, suitable for using on a normal driveway. The essential disadvantages of either above appliances are as follows:
(1) The white warning device for freeway applications is made of acrylic plastic which reflects the light source directly by means of the toothed structure inside its main body. The reflection effect is poor, and its reflecting spheroid is flat, therefore, dust can readily adhere to its surface and may weaken its reflecting effect day after day; PA0 (2) The grass green warning device for normal driveway application is of South African origin, there is no other supply source, therefore, its high price is not economical; PA0 (3) So far there is no new manufacturing know-how to provide varying colors, thus it is impossible to match the colors of the road markings.
In view of these prior art problems, the present invention is thus created to use potash-glass as the raw material for manufacturing a warning device. After the glass is pressed to form a main body, a tinfoil metal-powder is high pressure sprayed on its spherical surface, then the reflecting spheroid on the top of the warning device will be trimmed to remove the excess metal powder. Finally, a metal-oxide (e.g. silver oxide, plumbous oxide or gold sodium chloride etc.) will be sprayed either on the whole spherical surface or a semispherical surface of the reflecting spheroid, in order to show different colors on the reflecting spheroid.